This invention relates to an automated storage and retrieval apparatus for ultra low temperature freezers, and more particularly an apparatus that improves the overall quality of the climate associated with storing items therein.
Advancements in biotechnology and medical science require the analysis of ever-increasing numbers of various biological samples. Many biological samples must be stored at below-freezing temperatures in order to preserve them for future reference, analysis, or use. For example, DNA, RNA, cells and protein samples, as well as the reagents necessary for conducting various analyses of these samples, must be stored at ultra-cold temperatures to prevent degradation that would interfere with reliable analyses of the biological products.
Storage below xe2x88x9280xc2x0 C. is generally required for successful preservation of biomolecules, cells, and tissue (morphology and viability) for extended periods of time. However, shelf life and the ability to recover living cells are dramatically improved at about xe2x88x92196xc2x0 C. (xe2x88x92196xc2x0 C. being the boiling point of liquid nitrogen). The National Institute of Standards and Technology has suggested that the term cryogenics be applied to all temperatures below xe2x88x92150xc2x0 C. (xe2x88x92238xc2x0 F. or 123xc2x0 above absolute zero on the Kelvin scale). Some scientists regard the normal boiling point of oxygen (xe2x88x92183xc2x0 C. or xe2x88x92297xc2x0 F.), as the upper limit. The term ultra low temperature is probably not officially recognized by any standards body. However, it is generally agreed that a freezer refers to a storage device that operates from about xe2x88x925xc2x0 C. to xe2x88x9220xc2x0 C., an ultra low operates from about xe2x88x9250xc2x0 C. to about xe2x88x9290xc2x0 C., and a cryogenic freezer operates from about xe2x88x92140xc2x0 C. to xe2x88x92196xc2x0 C.
There are many problems associated with placement and retrieval of samples from ordinary laboratory freezer compartments. For instance, in an ordinary freezer compartment, containers of samples must be stored in front of and on top of each other to maximize use of the available space. Even if the containers are of standard sizes, and therefore easily stackable and even if a positional inventory of the samples is kept, it is still necessary to shuffle the containers around manually in order to retrieve a desired container. This is problematic because it requires keeping the freezer door open for possibly extended periods of time. Keeping the freezer door open causes the interior temperature of the freezer compartment to rise temporarily, which can cause thawing of samples housed near the door of the freezer. Once the freezer is closed and the temperature decreases, the samples refreeze. This repeated freezing and thawing can cause more rapid degradation of samples. Keeping the freezer door open also allows frost to build up in the freezer compartment. With repeated openings of the door, the frost eventually can freeze containers to the bottom of the freezer compartment or to each other. As a result, the door must be kept open longer in order to break containers out of the frost, which only exacerbates the problem.
The increasing need for high quality bio-repositories in hospitals, research institutions, and pharmaceutical clinical research laboratories provides a market for automated ultra-cold storage devices that will improve sample quality, organize storage, provide rapid access to all specimens, and maintain electronic records of all specimens stored within the container.
U.S. Pat. No. 5,921,102 to Vago, herein incorporated by reference, utilizes a storage apparatus particularly with automatic insertion and retrieval. Drawbacks of the Vago approach, but not limited thereto, are that it fails to provide the climate control associated with the freezer and the various interchanging devices, and other features and aspects.
There is therefore a need in the art for an automated cold storage apparatus, and related method thereof, that can provide, among other things a more organized storage and retrieval apparatus, less accumulation of moisture and frost within the cold storage compartment, less temperature fluctuation from sample withdrawal, and rapid random access to all specimens.
The present invention automated cold storage apparatus, and related method thereof, provides a sample process management system that is a revolutionary approach to the storage and retrieval of critical samples. The systemxe2x80x94a significant technological breakthrough in laboratory automationxe2x80x94is the first ultra low temperature robotic system capable of being validated. Samples in containers are stored and retrieved robotically through an airlock climate-control chamber (access means) that is automatically dehumidified by a dry gas purge, such as a carbon dioxide or nitrogen purge or the like. This purge rapidly reduces ambient humidity to a desirable relative humidity (RH), e.g., less than about 15% RH, virtually eliminating the accumulation of frost. Microplates or storage containers, or the like, are systematically identified using barcode technology, for example. Once through the climate-controlled chamber, the containers (i.e., samples) are robotically transferred to the rotary mechanism. This mechanism transports the containers to a derived nest location upon the storage means, such as a carousel or one of the stationary addresses. For illustrative purposes only, the carousel and stationary nests may have a combined capacity of 1,000 standard microplates. It is contemplated that various capacities may be designed.
The preferred embodiments of the present invention automated storage and retrieval apparatus, and related method thereof, operate at an ultra low temperature of about xe2x88x9250xc2x0 C. to about xe2x88x9290xc2x0 C. It should be understood that the apparatus may operate in a range of xe2x88x9250xc2x0 C. up to ambient temperature or greater. The normal design operating temperature of the freezer compartment of the present invention is about xe2x88x9280xc2x0 C. It should be noted that the present invention is contemplated to operate at conditions colder than ultra low temperatures in the range of about xe2x88x92140xc2x0 C. to about xe2x88x9290xc2x0 C. Conveniently, if the freezer fails for whatever reasonxe2x80x94maintenance or scheduled outagexe2x80x94then liquid carbon dioxide can be pumped into the system and keep it at approximately xe2x88x9278xc2x0 C. The ultra low freezer set point (approximately 78xc2x0 C.) of the apparatus can be backed up by installing a cylinder of liquid carbon dioxide.
In one aspect, the present invention features an automated storage and retrieval apparatus for storing containers at ultra low temperatures or other preferred temperatures. The apparatus comprising: a freezer compartment, the freezer compartment having a side wall; a storage carousel disposed inside the freezer compartment for holding the containers; a climate-controlled chamber disposed on the side wall; a climate system for controlling the climate of the chamber; and an interchange mechanism configured. The interchange mechanism is configured to: interchange a container between the interchange mechanism and the climate-controlled chamber while in a chamber exchange position, and interchange a container between the interchange mechanism and the carousel while in a carousel exchange position. The chamber also being configured to: isolate the container from the interchange mechanism as container is deposited from the exterior or placed into the exterior, and isolate the container from the exterior as container is exchanged between the chamber and the interchange mechanism.
In some embodiments, the carousel can be replaced with a stationary storage rack, and additional storage racks may be added. The interchange mechanism is configured to interchange a container between the interchange mechanism and the rack(s) while in a rack exchange position(s).
In a second aspect, the present invention provides an automated storage and retrieval apparatus for storing containers at ultra low temperatures or other preferred temperatures. The apparatus comprising: a freezer means for freezing the containers; a storage means disposed inside the freezer means for holding the containers; a chamber means for interchanging the containers between the exterior and the freezer means; a climate system control means for controlling the climate of the chamber means; and an interchange means. The interchange means for: interchanging a container between the interchange means and, the chamber means while in a chamber exchange position, and interchanging a container between the interchange means and the storage means while in a storage exchange position. The chamber means for: isolating the container from the interchange means as container is deposited from the exterior or placed into the exterior, and isolating the container from the exterior as container is exchanged between the chamber means and said interchange means.
In a third aspect, the present invention provides a method for automatically depositing and storing containers, as well as a method for storing and retrieving containers in a freezer compartment of an automated apparatus. The apparatus comprising: a freezer means for freezing the containers; a storage means disposed inside the freezer means for holding the containers; a chamber means for interchanging the containers between the exterior and the freezer means; a climate system control means for controlling the climate of the chamber means; and an interchange means. The interchange means for: interchanging a container between the interchange means and the chamber means while in a chamber exchange position, and interchanging a container between the interchange means and the storage means while in a storage exchange position. The chamber means for: isolating the container from the interchange means as container is deposited from the exterior or placed into the exterior, and isolating the container from the exterior as container is exchanged between the chamber means and said interchange means.
An advantage of the present invention automated storage and retrieval apparatus for ultra low temperature freezers, and related method thereof, is that the apparatus can operate in a stand-alone mode or can be integrated into a completely automated laboratory. It is scalable to meet the needs of small laboratories as well as large institutions that will require long-term storage of large numbers of samples.
Another advantage of the present invention is that the apparatus can be designed as a slide-in unit for existing ultra-cold freezers, which will keep the majority of the hardware in the door so as to be insulated from the freezer compartment, minimizing both the number of low-temperature hardware components and the actual alteration to the freezer itself. A reduced number of moving components is continuously exposed to the design temperature of about xe2x88x9280xc2x0 C., reducing the cost of production.
Further advantages of the present invention are attributed to the improved sample quality, lowered operating costs, and reduced maintenance of the automated storage and retrieval apparatus.
Finally, an advantage of the present invention is that it provides ultra-low temperature automation or lower and user-friendly information technology in a proven reliable manner.
These and other objects, along with advantages and features of the invention disclosed herein, will be made more apparent from the description, drawings and claims that follow.